A 19-year-old man who was recently released from jail was charged with first-degree murder yesterday in the slaying of a Prince George's County police officer.

Authorities said Ronnie L. White was detained Friday in Laurel after two men in a pickup believed to be stolen hit Cpl. Richard S. Findley in a parking lot near the 14700 block of Laurel-Bowie Road.

Findley and other officers from an elite squad had been attempting to box in the suspects when White, who police say was the driver, rammed Findley's cruiser. Findley got out of his cruiser and White hit him, dragging him on the front of the truck, police said. Findley, 39, suffered massive head trauma, and he died a short time later at Laurel Regional Hospital.

Maj. Daniel Dusseau, commander of the county's criminal investigations division, praised the quick work of the dozens of officers and detectives who swarmed nearby Laurel Square Apartments and searched door-to-door after Findley was hit. Police said they detained four people, including White, during the search.

Dusseau said additional arrests are likely. Sharon Taylor, a police spokeswoman, declined to say whether the other three people were still detained. She also declined to identify the person, one of the three, who was arrested Friday on unrelated charges or to specify what those charges were.

It was unclear yesterday whether White, of the 9100 block of Tumbleweed Run in the Laurel area of Howard County, had been assigned an attorney. Efforts to locate phone numbers for his family members were unsuccessful.

Court record show that in 2006, White was charged with first-degree assault and armed robbery; the case was dropped. Last year, he pleaded guilty to illegal possession of a firearm and, in a separate case, to drug possession. On Nov. 28, he was sentenced to more than six months in prison. It was unclear when he was released.

Findley was described as warm and friendly and as a person who didn't lose touch with friends, not even with the parents of his ex-wife. Denis Frazier, Findley's former father-in-law, said the two remained close even though he and his daughter, Findley's first wife, divorced more than a decade ago.

"He was one of these guys you just can't throw away," said Frazier, who lives in Wisconsin.

Frazier said Richard Findley's wife, Kelly Findley, called him at 5:20 a.m. yesterday to deliver the news. "She said it's been like a bad dream and she wished somebody would wake her up," Frazier said.

Findley lived in New Windsor, in Carroll County, about an hour's drive from where he worked in Prince George's. Frazier said Kelly Findley told him that although she usually didn't stir at dawn when her husband left for the long commute, she did Friday morning. "She woke up and said goodbye to him," Frazier said.